CMYK pen concept for designers

It seems the CMYK pen concept is so impressive even though no any description. Let’s imagine, perhaps as long as knowing the CMYK, you could use any color combined by the CMYK pen to draw on paper. It’s really cool for everyone who like drawing., not just for designers. unfortunately, CMYK pen is only a design concept at present. Hopefully the amazing gadget could be appeared as soon as possible.